--- old/src/hotspot/share/gc/shared/vmGCOperations.cpp	2018-09-04 14:50:31.151732240 +0000
+++ new/src/hotspot/share/gc/shared/vmGCOperations.cpp	2018-09-04 14:50:30.971730236 +0000
@@ -81,7 +81,8 @@
 }
 
 bool VM_GC_Operation::doit_prologue() {
-  assert(Thread::current()->is_Java_thread(), "just checking");
+  assert(Thread::current()->is_Java_thread() || 
+         Thread::current()->is_ConcurrentGC_thread(), "just checking");
   assert(((_gc_cause != GCCause::_no_gc) &&
           (_gc_cause != GCCause::_no_cause_specified)), "Illegal GCCause");
 
@@ -110,7 +111,8 @@
 
 
 void VM_GC_Operation::doit_epilogue() {
-  assert(Thread::current()->is_Java_thread(), "just checking");
+  assert(Thread::current()->is_Java_thread() || 
+         Thread::current()->is_ConcurrentGC_thread(), "just checking");
   // Clean up old interpreter OopMap entries that were replaced
   // during the GC thread root traversal.
   OopMapCache::cleanup_old_entries();